Circulating cooling system for piston internal combustion engines

ABSTRACT

A circulation cooling system for internal combustion engines with a cooling jacket and control devices which interrupt the cooling medium circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or the time after the cold start of the engine, above the first predetermined limit value initially confine the circulation to a closed circulation in by-passing a radiator and under avoidance of a fresh water exchange, and above a further predetermined temperature limit include the radiator, a heater heatexchanger and/or the fresh water exchange into the cooling medium circulation; vent lines arranged between vent line connections of the radiator, of the thermostat housing, of the cooling jacket, of the cooling medium valve, and/or of an expansion tank are adapted to be closed off by at least one float valve controlled by the cooling medium level.

United States Patent 1 1 Henning et al.

[451 Nov. 25, 1975 [75] Inventors: Richard I-Ienning, Munich; Erwin Schweiger, Dachau, both of Germany [73] Assignee: Bayerische Motoren We'rke Aktiengesellschaft, Germany 221 Filed: Mar. 22, 1974 21 Appl. No.2 453,807

[30] Foreign Application Priority Data Mar. 22, 1973 Germany 2314301 [52] US. Cl. l23/4l.54; 123/41.02; 123/41.08; 236/345; 237/8 C; 237/123 B [51] Int. Cl. F011 3/22 [58] Field of Search 237/123 B, 8 C; 236/345; 123/41.08, 41.01, 41.10, 41.54; 137/409,

3,162,182 12/1964 Gratzmuller l23/41.54

3,211,374 10/1965 Matulaitis 237/123 B 3,499,481 3/1970 Avrea 123/41.54 3,851,629 12/1974 Mayr l23/4l.08

Primary Exarrtiner--Charles J. Myhre Assistant ExaminerDaniel J. OConnor Attorney, Agent, or Firm-Craig & Antonelli [57] ABSTRACT A circulation cooling system for internal combustion engines with a cooling jacket and control devices which interrupt the cooling medium circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or the time after the cold start of the engine, above the first predetermined limit value initially confine the circulation to a closed circulation in by-passing a radiator and under avoidance of a fresh water exchange, and above a furthervpredete'rmined temperature limit include the radiator, a heater heatexchanger and/or the fresh water exchange into the cooling medium circulation; vent lines arranged between vent line connections of the radiator, of the thermostat housing, of the cooling jacket, of the cooling medium valve, and/or of an expansion tank are adapted to be closed off by at least one float valve controlled by the cooling medium level.

25 Claims, 5 Drawing Figures Sheet 1 of 5 US. Patent Nov. 25, 1975 U.S. Patent Nov. 25, 1975 Shet 2 of5 3,921,600

US. Patent Nov. 25, 1975 Sheet 3 of5 3,921,600

US. Patent Nov. 25, 1975 Sheet4 0f5 3,921,600

US Patent Nov. 25, 1975 Sheet50f5 3,921,600

CIRCULATING COOLING SYSTEM FOR PISTON INTERNAL COMBUSTION ENGINES The present invention relates to a circulating cooling system for piston internal combustion engines with a cooling jacket and control devices which interrupt the cooling medium circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/orof the time after the cold start of the engine, above the first predetermined limit value initially confine the circulation to a closed circulation bypassing a radiator and avoiding a fresh water exchange. and above a further predetermined temperature value incorporate the radiator, a heater heat-exchanger and- /or the fresh water exchange into the cooling circulation.

The aim of the present invention is to further improve such a circulating cooling system. The present invention consists for that purpose in that vent lines arranged between the vent connections of the radiator, of the thermostat housing, of the cooling jacket, of the cooling medium valve, and/or of an expansion tank are adapted to be closed off by at least one float valve controlled by the cooling medium level. Up to the first predetermined limit value of the temperature of the cooling medium, exclusively that portion of the cooling medium can be included in this manner into the warm-up operation which is disposed in the cooling jacket itself. Also no residual circulation of the cooling medium takes place through vent lines.

These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing, which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIGS. 1 and 2 are schematic views of a circulation cooling installation according to the present invention in the starting control phase and in the end control phase, respectively, during the warm-up operation of an internal combustion engine;

FIG. 3 is a side elevational view of a thermostat housing for a circulation cooling installation according to the present invention;

FIG. 4 is a longitudinal cross-sectional view taken along line IV- -IV in FIG. 5; and

FIG. 5 is an end elevational view of the thermostat housing according to FIGS. 3 and 4.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, the circulating cooling installation, schematically illustrated in FIGS. 1 and 2, of an internal combustion engine 1 includes a conventional cooling jacket with a first area or region 2 which is arranged in the cylinder block of the internal combustion engine and includes essentially the cylinder sliding surfaces of the pistons of the internal combustion engine 1. The second area orregion 3 of the cooling jacket is arranged in the cylinder head of the internal combustion engine 1. It includes, above all, the combustion zones. The latter are essentially the combustion spaces and the gas-exchange channels.

For the circulation of a cooling medium, the internal combustion engine 1 includes 'at the usual places a cooling medium inlet opening or aperture 4 and a cooling mediumdischarge opening or aperture 5 which are provided, respectively, at a geodetically low location in the first area 2 and at a geodetically high location in the second area 3 of the cooling jacket. A further geodetically high discharge opening or aperture 6 is formed in the second area 3 of the cooling jacket. Additionally. a further auxiliary discharge opening or-aperture 7 may be provided in the first area 2possibly also at the location of the discharge aperture 6.

A free. unobstructed cooling medium'line 8 leads from the cooling medium discharge aperture 5 to a radiator 9 and terminates in the latter at a geodetically high place. The cooling medium line 8 passes a thermostat housing 11 at the height of a branching place 10.

An expansion element 12 ofa cooling medium valve 13' protrudes into the branching place 10. which is equipped with a disk valve 14. The plate valve 14 is operable to close or open a control opening 15.

A radiator return line 16 leaves the radiator 9 at a geodetically low place, which connects the radiator 9 with the thermostat housing 11. The radiator return line 16 is completely or partially closed off or opened up in the thermostat housing 11 within the area of a control opening 17 by a disk valve 18. The disk valve 18, as also the disk valve 19, which is provided for the opening or closing of the control opening 20 of a bypass 20, are component parts of a three-way thermostat 21 which is arranged in the interior space of the thermostat housing 11. Both disk valves 18 and 19 are controlled by way of an expansion element 21' which carries out control movements corresponding to the temperature of the flow of the cooling medium through the control opening 17 out of the radiator 9 and through the control opening 20 out of the by-pass 20.

A return line 23 branches off from a combining place 22 in the thermostat housing 11, which is in communication with the suction side of a cooling medium pump 24. The cooling medium pump 24 supplies the cooling medium through a cooling medium line 25 by way of the cooling medium inlet aperture 4 into the first area 2 of the internal combustion engine 1.

Furthermore, a discharge line 27 coming from a heater heat-exchanger 26 terminates in the combining place 22; the discharge line 27 is again in communication with an expansion tank 28 by way of a line 29.

Additionally, an auxiliary circulation line 30 terminates in the discharge line 27; the auxiliary circulation line 30 is thereby connected either to the discharge aperture 7indicated in dash line-or in case of omission of the discharge aperture 7, by way of an auxiliary circulation line 30' to the place 31 between discharge aperture 6 and the heater heat-exchanger 26 to the feedline 32 for the heat-exchanger 26. A heater jacket 33 for a suction-line-throttle-valve 34 and a temperature value pick-up or transmitter 35 of conventional construction for a fuel metering mechanism of the internal combustion engine 1 are interconnected into this auxiliary circulation line 30. The feed line 32 is connected to the discharge aperture 6. The flow cross section of the cooling medium within the area of the discharge aperture 6 is controlled by means of a valve 36 with a disk valve 37. The control thereby takes place by way of an expansion element which projects into the second area 3.

Both the heat-exchanger 26 as also the auxiliary circulation line 30 may be connected directly to the discharge aperture 7 within the first area 2 of the cooling jacket. In this case, the discharge aperture 6 may be dispensed with. It is only important that the location of the discharge aperture 7 is so selected that a swirling or vortexting of the cooling medium disposed within the second area 3 does not occur during the warm-up operation of the internal combustion engine, and as a result thereof an accelerated warm-up of the cooling medium in the combustion zones is assured during the cold start. The last-mentioned variation in the solution is especially appropriate, when the internal combustion engine is started at extremely low ambient or outside tem peratures in order to feed to the heater for the inside space of the vehicle cooling medium heated up above the outside temperature as soon as possible.

In order that no air bubbles are enclosed during the filling up of the circulating cooling system with the cooling medium, which would endanger the troublefree operation of the cooling medium pump 24 as well as the cooling of the combustion zones. vent lines are provided according to the present invention. For purposes of-venting the radiator 9, a vent line 38 is connected thereto at a geodetically high location which terminates uncontrolled in the thermostat housing 11 upstream of the control opening 17. The termination place of this vent line 38 is located in the geodetically high areaof the thermostat housing 11. Adjacent to this termination place, a further vent line 39 branches off from the thermostat housing ll-also still upstream of the control aperture 17which is connected with the expansion tank 28. A still further vent line 41 terminates within the area 40 of the further vent line 39; the still further vent line 41 thereby branches off from the combining place 22 of the thermostat housing 11. The further vent line 39 tapers within the area 40, i.e., is constricted within this area 40. The tapering or constriction place is thereby constructed as seat for a float valve 42-.which with an increasing cooling medium level closes offthe further vent lines 39 and 41 against the rising cooling medium. The venting of the cooling system is ensured by the arrangement of these vent lines. At the same time, a circulation of the cooling medium through the vent lines, harmful for the rapid warm-up of the engine, is avoided by the float valve 42.

- In the first control phase, according to FIG. 1, the disk valve 14 of the. cooling medium valve 13 and the disk valve 18 of the three-way thermostat 21 close the control apertures 15 and 17, respectively, when the engine is cold and thus the cooling medium is cold. As a result thereof, the cooling medium present within the area of the cooling medium line 8, of the radiator 9 and of the return line 16 cannot flow to the cooling medium pump 24. Since additionally, the discharge opening 6 is closed by the disk valve 37, also no circulation of the cooling medium takes place even with a running cooling medium pump. As a result thereof, the cooling medium present within the second area 3 of the cooling jacket of the engine 1 remains stationary. i.e., does not move so that a reduced heat removal from the combustion zones exists in this area and simultaneously a more rapid warm-up of the cooling medium present in this area takes place. This action is therebeyond additionally favored in that the cooling medium present outside of the areas 2 and 3 of the cooling jacket does not partake in the warm-up operation of the engine. In this manner, a very rapid warm-up of the walls of the combustion zones to an operating temperature is attained in the illustrated position of the disk valves 14 and 18 of FIG. 1, in which favorable combustion conditions will establish themselves in the combustion spaces both with respect to the running properties of the engine as also with respect to smaller proportions in harmful exhaust gas components. In particular, cold-start enrichments of the fuel-air mixture can be omitted after a particularly short period of time.

During the warmup operation of the engine, all disk valves except for the disk valve 19 close the control openings coordinated thereto. During this control phase. a circulation of the cooling medium therefore takes place only if the discharge aperture 7 is provided within the first area 2 of the engine 1 and the auxiliary circulation line 30 is connected thereto or in case of I omission of the discharge aperture 6, the feed line 32 is connected by way of the auxiliary circulation line 30'.

The cooling medium supplied by the cooling medium pump 24 thereby flows through the cooling medium, line 25,-enters by way of the cooling medium inlet aper-- ture 4 into the first area 2 of the internal combustion engine 1, flows through this areaapproximately along the flow paths indicated in dash and dot linesbranches off into two streams, reaches with a first partial stream the auxiliary circulation line 30 through the dispump 24 by way of the return line 23. In the course of this circulation, the cooling medium follows the path indicated by the. arrows 43. In order to avoid in every case during the first control phase a cooling-off of the cooling medium by the heat-exchanger 26, it is appropriate under certain circumstances not to permit the cooling medium to flow through the heat-exchanger 26 at the beginning of this control phase, for example, controlled by a time switch. Such a switch may be ar ranged at the location 44 and may be a conventional 1 timer switch. The same purpose can also be achieved by the arrangement of a valve corresponding to the valve 36 at the location 44, whose control element is I disposed in the cooling medium stream coming out of the discharge aperture 7 and flowing constantly and uncontrolled through the auxiliary circulation line 30 and whose disk valve opens the auxiliary circulation line 30 to the feed line 32 only above a predetermined temperature of the cooling medium.

During this first control phase-apart from a thermosiphoning flow,a swirling or vortexing of the cooling medium present in the second area 3 is thus avoided. Overheating appearances of the internal combustion engine are precluded also under extreme loads during the warm-up operation in that the first control phase is timely terminated by response of the cooling medium valve 13.

By reference to FIG. 2, the second control phase will be described during the warm-up of the engine. The same reference numerals are thereby used for the individual parts of the cooling system as in FIG. 1.

With an increase of the cooling medium temperature, the valve 36 opens the discharge aperture 6. The prerequisites for a circulation of the cooling medium according to the arrows 45 are fulfilled thereby. The cooling medium supplied by the cooling medium pump 24 thereby reaches the first area 2 by way of the cooling medium'inlet aperture 4, from there reaches the second area 3 in order to flow thereafter through the discharge aperture 6 and through the feed line 32 into the heatexchanger 26. Out of the heat-exchanger 26, the cooling medium reaches the combining place 22 in the thermostat housing 11 by way of the discharge line 27. From there, the cooling medium returns uncontrolled to the cooling medium pump 24 by way of the return line 23. Additionally, there exists an auxiliary circulationassuming that in this embodiment the discharge aperture 7 is notpresent and that the auxiliary circulation line 30' starts from the place 31-whose flow path is designated by the arrows 46. The cooling medium thereby reaches the auxiliary circulation line 30 and 30 from the feed line 32, flows through the heat jacket 33 and flows into the discharge line 27 by way of the temperature pick-up 35.

The control of the valve 36 takes place by way of an expansion element which, at a predetermined temperature, so displaces the disk valve 37 that the discharge aperture 6 is opened. At this control temperature, however, the expansion elements of the cooling medium valve 13 and of the three-way thermostat 21 do not as yet respond. The associated disk valves remain in their positions closing the associated control openings. As a result thereof, neither a flow by way of the by-pass 20' through the control opening 15 nor a flow through the radiator 9 takes place in the second control phase.

in the course of the third control phase during the warm-up operation of the engine, the valve 35 is open and the cooling medium valve 13 opens the control opening 15 as soon as the cooling medium reaches a temperature, at which the combustion zones within the area of the cooling jacket'have a temperature sufficient for the operation of the engine without fuel enrichment and which is equal to or higher than the temperature at which the valve 36 opens, so that now also a circulation is possible by way of the by-pass 20' according to arrows 47. The control of thecooling medium valve 13 takes place by way of the expansion element 12 which is so arranged within the area of the geodetically high cooling medium discharge aperture that it is acted upon owing to thermo-siphon flow by the highest occurring temperature of the cooling medium in the second area 3, when the cooling medium is stationary or standing-still.

On the one hand, an excessive warm-up of the combustion zones and, on the other, an excessive cooling off of the cooling medium is avoided by the by-pass circulation 47, which would otherwise take place with a conduction of the cooling medium through the radiator 9. The remaining circulations through the heatexchanger 26 according to the arrows 45 and through the heater jacket 33 according to arrows 46 remain preserved unchanged in this control phase. A part of the cooling medium leaves the engine 1 through the cooling medium discharge aperture 5 during this control phase, flows around the disk valve 14 and by way of the by-pass 20', of the control opening and of the open control opening reaches the combining place 22 in the thermostat housing 11, in which it joins the flow path of the remaining circulations according to the arrows 45 and 46.

The warm-up operation of the engine terminates with the fourth control phase. The cooling medium thereby reaches a temperature, at which also the disk valve 18 controlling the flow of the cooling medium through the radiator 9, which again is controlled by an expansion element, opens up the control opening 17. With the beginning of the opening of thecontrol aperture 17, the disk valve 19 increasingly closes the control aperture 20. As a result of the adjustment of the disk valve 19, the by-pass 20' is increasingly closed so that in addition to the described circulation according to the arrows 45 and to the auxiliary circulation according to the arrows 46, the radiator-circulation according to the arrows 48 is added. The cooling medium quantity forming the radiator-circulation reaches the radiator 9 uncontrolled out of the cooling medium discharge aperture 5 through the cooling medium line 8. The cooling medium gives off heat in the radiator 9 and reaches thereafter the thermostat housing 11 by way of the return line 16. The cooling medium circumcirculates thereat the disk valve 18 and mixes in the combining place 22 with the circulation described hereinabove and designated by arrows 45, andto the extent that it is not yet completely interrupted-with the by-pass circulation 47.

A geodetic drop is provided for venting purposes. contrary to the schematic arrangement shown in FIGS. 1 and 2, between the parts of the cooling system to be vented so that the cooling medium level 28' in the expansion tank 28, which has an automatic vent mechanism of conventional construction (not shown), is disposed at all times at the geodetically highest place of the cooling system.

The thermostat housing 59 illustrated in FIGS. 3 to 5 corresponds in principle to the thermostat housing 11 in FIGS. 1 and 2. The same reference numerals will be used for the cooling medium lines and for the vent lines as have been used in connection with FIGS. 1 and 2.

The thermostat housing 59 involves acasting which is made preferably of aluminum or other known lightmetal alloys. it is composed externally essentially ofa housing part 60 and of a housing cover 61. The housing cover 61 is secured at the housing part 60 by means of bolts 62. A seal 63 is provided between the abutment surfaces of the housing part 60 and of the housing cover 61.

The housing part 60 includes a fastening flange with fastening eyes 64 and 65 (FIG. 3) for its fastening at the engine. Additionally, the connecting nipples 66, 67 and 68 for the cooling medium line 8 leading freely or unobstructedly to the radiator, for the discharge line 27 and for the return line 23, respectively, are additionally provided at the housing part 60.

The connecting nipple 69 is provided at the housing cover 61 for the radiator return line 16. For purpose of venting the thermostat housing 59, the vent lines 38 and 39 terminate in the housing 61 thereof at geodetically high places. The further vent line 41 branches off from the vent line 39.

The flow directions of the cooling medium flowing into or out of the thermostat housing 59 are indicated by arrows 70, 71, 72 and 73.

At the height of a first separating plane 74 between the housing part 60 and the housing cover 61 terminates an approximately cylindrical housing insert 75 within the thermostat housing 59; the housing insert 75 encloses a combining place 76 and is supported with its end opposite the first separating plane 74 against a fastening flange 78 of a cooling medium valve 79. The fastening flange 78 rests on the sealing ring 80 which in its turn is embedded in a recess within the housing part 60. The housing insert 75 and the fastening flange 78 abut against one another in a second separating plane 81. By means of bolts 62, the housing insert 75 is retained 7 against the sealing ring 82 and the fastening flange 83 of the three-way thermostat 84 against the shoulder 85 of a recess within the housing cover 61.

The three-way thermostat 84 and the cooling medium valve 79 are installed into the thermostat housing 59 coaxially aligned to one another. They have essentially the same construction as can be seen from the schematic illustration in FIGS. land 2. The three-way thermostat 84 includes an expansion element 86 which is supported at the bracket-like support member 88 of yoke shape by way of the piston rod 87 and, beginning with, apredetermined temperature, moves in the direction toward the cooling medium valve 79. The disk valves 90 and 91 mounted on the expansion element 86, which correspond to the disk valves 18 and 19 illustrated in FIGS. 1 and 2, are therebydisplaced in the same direction, on the one hand, away from the valve seat 92 and, on the other, toward the valve seat 93. As a result thereof, the control openings 94 and 95 are, respectively, opened and closed. The movement of the expansion element 86 takes place against the resistance of a compression spring 96 which is supported, on the one hand, at a further bracket-like curved support member 97 which is connected to the fastening flange 83 and to the support member 88 and is slidingly supported on an outer surface of the expansion element 86, and on the other, at the surface of the disk valve 90 facing the curved support member 97. As a result thereof, at a temperature of the cooling medium which lies below the control temperature of the expansion el ement' 86, the expansion element 86 and therewith also the disk valve 90 as also the disk valve 91 are moved back in a direction toward the support member 88. The disk valve 90 thereby buts sealingly against its valve seat 92.

-The disk valve 91 is axially displaceably mounted on the tapered end of the expansion element 86 and is axi ally secured by a ring 91 In order that a sealing abutment of the disk valve 91 at its valve seat 93 is assured, a compression spring 98 is provided which is supported at the surface of the disk valve 91 facing the curved support member 97and at a collar 99 of the expansion element 86. The valve seat 93 may, as illustrated in this embodiment, be constructed in one piece with the housing insert 75, as apart of this housing insert or at the fastening'flange 78 or at the curved bracket-like support member 100 of the cooling medium valve 79.

The construction of the cooling medium valve 79 is similar to that of the three-way thermostat 84. Also in this case the expansion element 101 is moved in the direction away from the curved support member 100 at a predetermined temperature by means of the piston rod 102 which is supported at the curved support member 100.'As a result thereof, the disk valve 103 secured on the expansion element 101 is moved away from the valve seat 106 against the force of the compression spring 104 which is supported at the bracket-like, yokeshaped support member 105 and at the disk valve 103. The support members 100 and 105, the valve seat 106 which is a part of the fastening flange and the fastening flange 78 are rigidly connected with each other.

The cooling medium valve 79 projects with its expan ,sion element 101 into the cooling mediumline 8. Up to its control temperature, the cooling medium valve 79 closes the control opening 107 and, together with the also-closed disk valve 90 of the three-way thermostat 84, prevents thereby any cooling medium circulation through the by-pass and through the radiatorv With a temperature increase of the cooling medium in the cooling medium line 8 by thermo-siphoning flow out of the engine, the cooling medium valve 79 responds, and the disk valve 103 opens up the control aperture 107 so that the cooling. medium reaches the return line 23 through the control opening in the by-pass 20'. With a further temperature increase of the cooling medium,

the three-way thermostat 84 responds, opens with its disk valve 90 the control opening 94 and closes with its disk valve 91 the control opening 95. As a result thereof, the by-pass 20 through the control opening 107 is increasingly interrupted and the cooling medium flows to the radiator 9 by way of the cooling medium,

line 8. From there, it returns into the housing cover 61 by way of the radiator return line 16 and flows through the control opening 94 in the combining place 76 and from there to the cooling medium pump 24 by way of the return line 23.

The connecting nipples 109 and 110 contain parts of the vent lines 39 and 38 for the conduction of the air to the expansion tank 28 and from the radiator 9. The

connecting nipple 109 is illustrated incross section int FIG. 5 so that the float valve 111, schematically illustrated in FIGS. 1 and 2, becomes visible. The float valve 111 includes a conical valve body 112 with a cylindrical guide section 113 which are combined into a structural member. The associated valve seat 114 is constructed of complementary conical shape. The vent lines 39 and 41 terminate in the surface of the valve seat 114. The location of the discharge of the vent line 41 is designated by reference numeral 115.

As soon as the cooling medium level reaches the float valve 111 during the filling of the cooling system with,

cooling medium, the float valve 111 is pressed against the surface of the valve seat 114. As a result thereofQa penetration of the cooling medium into the vent line 39 leaving the thermostat housing is prevented and a cooling medium circulation through the vent lines 38 and 39 which is possible as such, by way of the expansion tank 28, of the line 29, the discharge, line 27, the thermostat housing 11, the return line 23, the cooling medium pump 24, the cooling medium line 25, the areas 2 and 3 of the cooling jacket of the engine 1, the cooling medium line 8, the radiator 9, the radiator return line 16 and the vent line 38 in parallel thereto back into the interior of the housing cover 61 is avoided thereby. Also, a shortened cooling medium circulation which in particular does not include the expansion tank 28 by way "of the vent line 41 is precluded.

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and we therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What we claim is:

1. A circulation cooling installation in an internal combustion engine which includes cooling jacket means and control means operable to interrupt the cooling medium circulation through the cooling jacket means at least within the area of the combustion zones up to a first predetermined limit value after the cold start of the engine, above the first predetermined limit value to confine the cooling medium circulation at first to a closed circulation by-passing a radiator means and avoiding a fresh water exchange, and above a further predetermined limit value include into the cooling medium circulation, the radiator means and at least one of the two parts consisting of heater heat-exchanger means and fresh water exchange, characterized by vent line means which are arranged between vent connections of at least some of the parts consisting of radiator means, thermostat housing means, cooling jacket means, cooling valve means and an expansion tank means, said vent line means being operable to be closed off by at least one float valve means controlled by the level of the cooling medium for preventing circulation of the cooling medium through said vent line means.

2. An installation according to claim 1, characterized in that the first predetermined limit value is the temperature of the engine.

3. An installation according to claim 1, characterized in that the first limit value is a predetermined period of time after the cold start of the engine.

4. An installation according to claim 3, characterized in that the first predetermined limit value is the temperature of the engine.

5. An installation according to claim 1, characterized in that the vent line means are arranged between the vent connections of the radiator means, of the thermostat housing means, of the cooling jacket means, and of the cooling medium valve means as well as of the expansion tank means.

6. An installation according to claim 1, characterized in that the vent line means of the radiator means terminates uncontrolled in the thermostat housing means at a geodetic high place which is connected with the radiator means by way of a radiator return line, and in that the float valve means controls a vent connection which discharges out of this place of the thermostat housing means, and in that further vent line means from a combining place of at least one of the two parts consisting of three-way thermostat means and cooling jacket means terminate in the float valve means in such a manner as to be operable to be closed with respect to one another.

7. An installation according to claim 6, characterized in that the further vent line means from the combining place of the three-way thermostat means as well as from the cooling jacket means terminate in the float valve means.

8. An installation according to claim 6, characterized in that the float valve means has a conically shaped valve seat.

9. An installation according to claim 8, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.

10. An installation according to claim 8, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.

11. An installation according to claim 8, characterized in that the vent line means terminate in the valve seat surface of the conically shaped valve seat.

12. An installation according to claim 11, characterized in that the vent line means terminate downstream 10 of the valve seat surface of the conically shaped valve seat.

13. An installation according to claim 11, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.

14. An installation according to claim 8, characterized in that the float valve means includes a float means and a conically shaped valve body combined together with the float means into a structural part having a cylindrical guide section.

15. An installation according to claim 14, characterized in that the sections of the vent line means arranged in the thermostat housing means, the valve seat of the float valve means and the guide means of the float means are constructed as bores provided in the thermostat housing means.

16. An installation according to claim 15, characterized in that the vent line means are arranged between the vent connections of the radiator means, of the ther' mostat housing means, of the cooling jacket means, and of the cooling medium valve means as well as of the expansion tank means.

17. An installation according to claim 1, characterized in that the float valve means has a conically shaped valve seat.

18. An installation according to claim 17, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.

19. An installation according to claim 17, characterized in that the -vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.

20. An installation according to claim 17, characterized in that the vent line means terminate in the valve seat surface of the conically shaped valve seat.

21. An installation according to claim 20, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.

22. An installation according to claim 20, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.

23. An installation according to claim 1, characterized in that the float valve means includes a float means and a conically shaped valve body combined together with the float means into a structural part having a cylindrical guide section.

24. An installation according to claim 23, characterized in that the float valve means has a conically shaped valve seat.

25. An installation according to claim 23, characterized in that the sections of the vent line means arranged in the thermostat housing means, the valve seat of the float valve means and the guide means of the float means are constructed as bores provided in the thermostat housing means. 

1. A circulation cooling installation in an internal combustion engine which includes cooling jacket means and control means operable to interrupt the cooling medium circulation through the cooling jacket means at least within the area of the combustion zones up to a first predetermined limit value after the cold start of the engine, above the first predetermined limit value to confine the cooling medium circulation at first to a closed circulation by-passing a radiator means and avoiding a fresh water exchange, and above a further predetermined limit value include into the cooling medium circulation, the radiator means and at least one of the two parts consisting of heater heatexchanger means and fresh water exchange, characterized by vent line means which are arranged between vent connections of at least some of the parts consisting of radiator means, thermostat housing means, cooling jacket means, cooling valve means and an expansion tank means, said vent line means being operable to be closed off by at least one float valve means controlled by the level of the cooling medium for preventing circulation of the cooling medium through said vent line means.
 2. An installation according to claim 1, characterized in that the first predetermined limit value is the temperature of the engine.
 3. An installation according to claim 1, characterized in that the first limit value is a predetermined period of time after the cold start of the engine.
 4. An installation according to claim 3, characterized in that the first predetermined limit value is the temperature of the engine.
 5. An installation according to claim 1, characterized in that the vent line means are arranged between the vent connections of the radiator means, of the thermostat housing means, of the cooling jacket means, and of the cooling medium valve means as well as of the expansion tank means.
 6. An installation according to claim 1, characterized in that the vent line means of the radiator means terminates uncontrolled in the thermostat housing means at a geodetic high place which is connected with the radiator means by way of a radiator return line, and in that the float valve means controls a vent conNection which discharges out of this place of the thermostat housing means, and in that further vent line means from a combining place of at least one of the two parts consisting of three-way thermostat means and cooling jacket means terminate in the float valve means in such a manner as to be operable to be closed with respect to one another.
 7. An installation according to claim 6, characterized in that the further vent line means from the combining place of the three-way thermostat means as well as from the cooling jacket means terminate in the float valve means.
 8. An installation according to claim 6, characterized in that the float valve means has a conically shaped valve seat.
 9. An installation according to claim 8, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.
 10. An installation according to claim 8, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.
 11. An installation according to claim 8, characterized in that the vent line means terminate in the valve seat surface of the conically shaped valve seat.
 12. An installation according to claim 11, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.
 13. An installation according to claim 11, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.
 14. An installation according to claim 8, characterized in that the float valve means includes a float means and a conically shaped valve body combined together with the float means into a structural part having a cylindrical guide section.
 15. An installation according to claim 14, characterized in that the sections of the vent line means arranged in the thermostat housing means, the valve seat of the float valve means and the guide means of the float means are constructed as bores provided in the thermostat housing means.
 16. An installation according to claim 15, characterized in that the vent line means are arranged between the vent connections of the radiator means, of the thermostat housing means, of the cooling jacket means, and of the cooling medium valve means as well as of the expansion tank means.
 17. An installation according to claim 1, characterized in that the float valve means has a conically shaped valve seat.
 18. An installation according to claim 17, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.
 19. An installation according to claim 17, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.
 20. An installation according to claim 17, characterized in that the vent line means terminate in the valve seat surface of the conically shaped valve seat.
 21. An installation according to claim 20, characterized in that the vent line means terminate downstream of the valve seat surface of the conically shaped valve seat.
 22. An installation according to claim 20, characterized in that the vent line means terminate upstream of the valve seat surface of the conically shaped valve seat.
 23. An installation according to claim 1, characterized in that the float valve means includes a float means and a conically shaped valve body combined together with the float means into a structural part having a cylindrical guide section.
 24. An installation according to claim 23, characterized in that the float valve means has a conically shaped valve seat.
 25. An installation according to claim 23, characterized in that the sections of the vent line means arranged in the thermostat housing means, the valve seat of the float valve means and the guide means of the float means are constructed as bores provided in the thermostat housing means. 